npu2-opencapi: Configure NPU for OpenCAPI

Scan the device tree for NPUs with OpenCAPI links and configure the NPU per
the initialisation sequence in the NPU OpenCAPI workbook.

Training of individual links and setup of per-AFU/link configuration will
be in a later patch.

Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

3 files changed, 833 insertions, 0 deletions

diff --git a/hw/Makefile.inc b/hw/Makefile.inc
index f31ba58..15bf5cf 100644
--- a/hw/Makefile.inc
+++ b/hw/Makefile.inc
@@ -8,6 +8,8 @@ HW_OBJS += phb3.o sfc-ctrl.o fake-rtc.o bt.o p8-i2c.o prd.o
 HW_OBJS += dts.o lpc-rtc.o npu.o npu-hw-procedures.o xive.o phb4.o
 HW_OBJS += fake-nvram.o lpc-mbox.o npu2.o npu2-hw-procedures.o
 HW_OBJS += npu2-common.o phys-map.o sbe-p9.o capp.o occ-sensor.o vas.o
+HW_OBJS += npu2-common.o npu2-opencapi.o phys-map.o sbe-p9.o capp.o occ-sensor.o
+HW_OBJS += vas.o
 HW=hw/built-in.a
 
 # FIXME hack this for now
diff --git a/hw/npu2-opencapi.c b/hw/npu2-opencapi.c
new file mode 100644
index 0000000..7851120
--- /dev/null
+++ b/hw/npu2-opencapi.c
@@ -0,0 +1,822 @@
+/* Copyright 2013-2018 IBM Corp.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+ * Support for OpenCAPI on POWER9 NPUs
+ *
+ * This file provides support for OpenCAPI as implemented on POWER9.
+ *
+ * At present, we initialise the NPU separately from the NVLink code in npu2.c.
+ * As such, we don't currently support mixed NVLink and OpenCAPI configurations
+ * on the same NPU for machines such as Witherspoon.
+ *
+ * Procedure references in this file are to the POWER9 OpenCAPI NPU Workbook
+ * (IBM internal document).
+ *
+ * TODO:
+ *   - Support for mixed NVLink and OpenCAPI on the same NPU
+ *   - Support for link ganging (one AFU using multiple links)
+ *   - Link reset and error handling
+ *   - Presence detection
+ *   - Consume HDAT NPU information
+ *   - LPC Memory support
+ */
+
+#include <skiboot.h>
+#include <xscom.h>
+#include <io.h>
+#include <timebase.h>
+#include <pci.h>
+#include <pci-cfg.h>
+#include <pci-slot.h>
+#include <interrupts.h>
+#include <opal.h>
+#include <opal-api.h>
+#include <npu2.h>
+#include <npu2-regs.h>
+#include <phys-map.h>
+#include <xive.h>
+#include <i2c.h>
+
+#define NPU_IRQ_LEVELS		35
+
+static inline uint64_t index_to_stack(uint64_t index) {
+	switch (index) {
+	case 2:
+	case 3:
+		return NPU2_STACK_STCK_1;
+		break;
+	case 4:
+	case 5:
+		return NPU2_STACK_STCK_2;
+		break;
+	default:
+		assert(false);
+	}
+}
+
+static inline uint64_t index_to_stacku(uint64_t index) {
+	switch (index) {
+	case 2:
+	case 3:
+		return NPU2_STACK_STCK_1U;
+		break;
+	case 4:
+	case 5:
+		return NPU2_STACK_STCK_2U;
+		break;
+	default:
+		assert(false);
+	}
+}
+
+static inline uint64_t index_to_block(uint64_t index) {
+	switch (index) {
+	case 2:
+	case 4:
+		return NPU2_BLOCK_OTL0;
+		break;
+	case 3:
+	case 5:
+		return NPU2_BLOCK_OTL1;
+		break;
+	default:
+		assert(false);
+	}
+}
+
+/* Procedure 13.1.3.1 - select OCAPI vs NVLink for bricks 2-3/4-5 */
+
+static void set_transport_mux_controls(uint32_t gcid, uint32_t scom_base,
+				       int index, enum npu2_dev_type type)
+{
+	/* Step 1 - Set Transport MUX controls to select correct OTL or NTL */
+	uint64_t reg;
+	uint64_t field;
+
+	/* TODO: Rework this to select for NVLink too */
+	assert(type == NPU2_DEV_TYPE_OPENCAPI);
+
+	prlog(PR_DEBUG, "OCAPI: %s: Setting transport mux controls\n", __func__);
+
+	/* Optical IO Transport Mux Config for Bricks 0-2 and 4-5 */
+	reg = npu2_scom_read(gcid, scom_base, NPU2_MISC_OPTICAL_IO_CFG0,
+			     NPU2_MISC_DA_LEN_8B);
+	switch (index) {
+	case 0:
+	case 1:
+		/* not valid for OpenCAPI */
+		assert(false);
+		break;
+	case 2:	 /* OTL1.0 */
+		field = GETFIELD(NPU2_MISC_OPTICAL_IO_CFG0_NDLMUX_BRK0TO2, reg);
+		field &= ~0b100;
+		reg = SETFIELD(NPU2_MISC_OPTICAL_IO_CFG0_NDLMUX_BRK0TO2, reg,
+			       field);
+		field = GETFIELD(NPU2_MISC_OPTICAL_IO_CFG0_OCMUX_BRK0TO1, reg);
+		field |= 0b10;
+		reg = SETFIELD(NPU2_MISC_OPTICAL_IO_CFG0_OCMUX_BRK0TO1, reg,
+			       field);
+		break;
+	case 3:	 /* OTL1.1 */
+		field = GETFIELD(NPU2_MISC_OPTICAL_IO_CFG0_NDLMUX_BRK0TO2, reg);
+		field &= ~0b010;
+		reg = SETFIELD(NPU2_MISC_OPTICAL_IO_CFG0_NDLMUX_BRK0TO2, reg,
+			       field);
+		field = GETFIELD(NPU2_MISC_OPTICAL_IO_CFG0_OCMUX_BRK0TO1, reg);
+		field |= 0b01;
+		reg = SETFIELD(NPU2_MISC_OPTICAL_IO_CFG0_OCMUX_BRK0TO1, reg,
+			       field);
+		break;
+	case 4:	 /* OTL2.0 */
+		field = GETFIELD(NPU2_MISC_OPTICAL_IO_CFG0_OCMUX_BRK4TO5, reg);
+		field |= 0b10;
+		reg = SETFIELD(NPU2_MISC_OPTICAL_IO_CFG0_OCMUX_BRK4TO5, reg,
+			       field);
+		break;
+	case 5:	 /* OTL2.1 */
+		field = GETFIELD(NPU2_MISC_OPTICAL_IO_CFG0_OCMUX_BRK4TO5, reg);
+		field |= 0b01;
+		reg = SETFIELD(NPU2_MISC_OPTICAL_IO_CFG0_OCMUX_BRK4TO5, reg,
+			       field);
+		break;
+	default:
+		assert(false);
+	}
+	npu2_scom_write(gcid, scom_base, NPU2_MISC_OPTICAL_IO_CFG0,
+			NPU2_MISC_DA_LEN_8B, reg);
+
+	/*
+	 * PowerBus Optical Miscellaneous Config Register - select
+	 * OpenCAPI for b4/5 and A-Link for b3
+	 */
+	xscom_read(gcid, PU_IOE_PB_MISC_CFG, &reg);
+	switch (index) {
+	case 0:
+	case 1:
+	case 2:
+	case 3:
+		break;
+	case 4:
+		reg = SETFIELD(PU_IOE_PB_MISC_CFG_SEL_04_NPU_NOT_PB, reg, 1);
+		break;
+	case 5:
+		reg = SETFIELD(PU_IOE_PB_MISC_CFG_SEL_05_NPU_NOT_PB, reg, 1);
+		break;
+	}
+	xscom_write(gcid, PU_IOE_PB_MISC_CFG, reg);
+}
+
+static void enable_odl_phy_mux(uint32_t gcid, int index)
+{
+	uint64_t reg;
+	uint64_t phy_config_scom;
+	prlog(PR_DEBUG, "OCAPI: %s: Enabling ODL to PHY MUXes\n", __func__);
+	/* Step 2 - Enable MUXes for ODL to PHY connection */
+	switch (index) {
+	case 2:
+	case 3:
+		phy_config_scom = OBUS_LL0_IOOL_PHY_CONFIG;
+		break;
+	case 4:
+	case 5:
+		phy_config_scom = OBUS_LL3_IOOL_PHY_CONFIG;
+		break;
+	default:
+		assert(false);
+	}
+
+	/* PowerBus OLL PHY Training Config Register */
+	xscom_read(gcid, phy_config_scom, &reg);
+
+	/* Enable ODLs to use shared PHYs */
+	reg |= OBUS_IOOL_PHY_CONFIG_ODL0_ENABLED;
+	reg |= OBUS_IOOL_PHY_CONFIG_ODL1_ENABLED;
+
+	/*
+	 * Based on the platform, we may have to activate an extra mux
+	 * to connect the ODL to the right set of lanes.
+	 *
+	 * FIXME: to be checked once we have merged with nvlink
+	 * code. Need to verify that it's a platform parameter and not
+	 * slot-dependent
+	 */
+	if (platform.ocapi->odl_phy_swap)
+		reg |= OBUS_IOOL_PHY_CONFIG_ODL_PHY_SWAP;
+	else
+		reg &= ~OBUS_IOOL_PHY_CONFIG_ODL_PHY_SWAP;
+
+	/* Disable A-Link link layers */
+	reg &= ~OBUS_IOOL_PHY_CONFIG_LINK0_OLL_ENABLED;
+	reg &= ~OBUS_IOOL_PHY_CONFIG_LINK1_OLL_ENABLED;
+
+	/* Disable NV-Link link layers */
+	reg &= ~OBUS_IOOL_PHY_CONFIG_NV0_NPU_ENABLED;
+	reg &= ~OBUS_IOOL_PHY_CONFIG_NV1_NPU_ENABLED;
+	reg &= ~OBUS_IOOL_PHY_CONFIG_NV2_NPU_ENABLED;
+	xscom_write(gcid, phy_config_scom, reg);
+}
+
+static void disable_alink_fp(uint32_t gcid)
+{
+	uint64_t reg = 0;
+
+	prlog(PR_DEBUG, "OCAPI: %s: Disabling A-Link framer/parsers\n", __func__);
+	/* Step 3 - Disable A-Link framers/parsers */
+	/* TODO: Confirm if needed on OPAL system */
+
+	reg |= PU_IOE_PB_FP_CFG_FP0_FMR_DISABLE;
+	reg |= PU_IOE_PB_FP_CFG_FP0_PRS_DISABLE;
+	reg |= PU_IOE_PB_FP_CFG_FP1_FMR_DISABLE;
+	reg |= PU_IOE_PB_FP_CFG_FP1_PRS_DISABLE;
+	xscom_write(gcid, PU_IOE_PB_FP01_CFG, reg);
+	xscom_write(gcid, PU_IOE_PB_FP23_CFG, reg);
+	xscom_write(gcid, PU_IOE_PB_FP45_CFG, reg);
+	xscom_write(gcid, PU_IOE_PB_FP67_CFG, reg);
+}
+
+static void enable_xsl_clocks(uint32_t gcid, uint32_t scom_base, int index)
+{
+	/* Step 5 - Enable Clocks in XSL */
+
+	prlog(PR_DEBUG, "OCAPI: %s: Enable clocks in XSL\n", __func__);
+
+	npu2_scom_write(gcid, scom_base, NPU2_REG_OFFSET(index_to_stack(index),
+							 NPU2_BLOCK_XSL,
+							 NPU2_XSL_WRAP_CFG),
+			NPU2_MISC_DA_LEN_8B, NPU2_XSL_WRAP_CFG_XSLO_CLOCK_ENABLE);
+}
+
+#define CQ_CTL_STATUS_TIMEOUT	10 /* milliseconds */
+
+static int set_fence_control(uint32_t gcid, uint32_t scom_base,
+			     int index, uint8_t status)
+{
+	int stack, block;
+	uint64_t reg, status_field;
+	uint8_t status_val;
+	uint64_t fence_control;
+	uint64_t timeout = mftb() + msecs_to_tb(CQ_CTL_STATUS_TIMEOUT);
+
+	stack = index_to_stack(index);
+	block = index_to_block(index);
+
+	fence_control = NPU2_REG_OFFSET(stack, NPU2_BLOCK_CTL,
+					block == NPU2_BLOCK_OTL0 ?
+					NPU2_CQ_CTL_FENCE_CONTROL_0 :
+					NPU2_CQ_CTL_FENCE_CONTROL_1);
+
+	reg = SETFIELD(NPU2_CQ_CTL_FENCE_CONTROL_REQUEST_FENCE, 0ull, status);
+	npu2_scom_write(gcid, scom_base, fence_control,
+			NPU2_MISC_DA_LEN_8B, reg);
+
+	/* Wait for fence status to update */
+	if (index_to_block(index) == NPU2_BLOCK_OTL0)
+		status_field = NPU2_CQ_CTL_STATUS_BRK0_AM_FENCED;
+	else
+		status_field = NPU2_CQ_CTL_STATUS_BRK1_AM_FENCED;
+
+	do {
+		reg = npu2_scom_read(gcid, scom_base,
+				     NPU2_REG_OFFSET(index_to_stack(index),
+						     NPU2_BLOCK_CTL,
+						     NPU2_CQ_CTL_STATUS),
+				     NPU2_MISC_DA_LEN_8B);
+		status_val = GETFIELD(status_field, reg);
+		if (status_val == status)
+			return OPAL_SUCCESS;
+		time_wait_ms(1);
+	} while (tb_compare(mftb(), timeout) == TB_ABEFOREB);
+
+	/**
+	 * @fwts-label OCAPIFenceStatusTimeout
+	 * @fwts-advice The NPU fence status did not update as expected. This
+	 * could be the result of a firmware or hardware bug. OpenCAPI
+	 * functionality could be broken.
+	 */
+	prlog(PR_ERR,
+	      "OCAPI: Fence status for brick %d stuck: expected 0x%x, got 0x%x\n",
+	      index, status, status_val);
+	return OPAL_HARDWARE;
+}
+
+static void set_npcq_config(uint32_t gcid, uint32_t scom_base, int index)
+{
+	uint64_t reg, stack, block;
+
+	prlog(PR_DEBUG, "OCAPI: %s: Set NPCQ Config\n", __func__);
+	/* Step 6 - Set NPCQ configuration */
+	/* CQ_CTL Misc Config Register #0 */
+	stack = index_to_stack(index);
+	block = index_to_block(index);
+
+	/* Enable OTL */
+	npu2_scom_write(gcid, scom_base, NPU2_OTL_CONFIG0(stack, block),
+			NPU2_MISC_DA_LEN_8B, NPU2_OTL_CONFIG0_EN);
+	set_fence_control(gcid, scom_base, index, 0b01);
+	reg = npu2_scom_read(gcid, scom_base,
+			     NPU2_REG_OFFSET(stack, NPU2_BLOCK_CTL,
+					     NPU2_CQ_CTL_MISC_CFG),
+			     NPU2_MISC_DA_LEN_8B);
+	/* Set OCAPI mode */
+	reg |= NPU2_CQ_CTL_MISC_CFG_CONFIG_OCAPI_MODE;
+	if (block == NPU2_BLOCK_OTL0)
+		reg |= NPU2_CQ_CTL_MISC_CFG_CONFIG_OTL0_ENABLE;
+	else
+		reg |= NPU2_CQ_CTL_MISC_CFG_CONFIG_OTL1_ENABLE;
+	npu2_scom_write(gcid, scom_base,
+			NPU2_REG_OFFSET(stack, NPU2_BLOCK_CTL,
+					NPU2_CQ_CTL_MISC_CFG),
+			NPU2_MISC_DA_LEN_8B, reg);
+
+	/* NPU Fenced */
+	set_fence_control(gcid, scom_base, index, 0b11);
+
+	/* NPU Half Fenced */
+	set_fence_control(gcid, scom_base, index, 0b10);
+
+	/* CQ_DAT Misc Config Register #1 */
+	reg = npu2_scom_read(gcid, scom_base,
+			     NPU2_REG_OFFSET(stack, NPU2_BLOCK_DAT,
+					     NPU2_CQ_DAT_MISC_CFG),
+			     NPU2_MISC_DA_LEN_8B);
+	/* Set OCAPI mode for bricks 2-5 */
+	reg |= NPU2_CQ_DAT_MISC_CFG_CONFIG_OCAPI_MODE;
+	npu2_scom_write(gcid, scom_base,
+			NPU2_REG_OFFSET(stack, NPU2_BLOCK_DAT,
+					NPU2_CQ_DAT_MISC_CFG),
+			NPU2_MISC_DA_LEN_8B, reg);
+
+	/* CQ_SM Misc Config Register #0 */
+	for (block = NPU2_BLOCK_SM_0; block <= NPU2_BLOCK_SM_3; block++) {
+		reg = npu2_scom_read(gcid, scom_base,
+				     NPU2_REG_OFFSET(stack, block,
+						     NPU2_CQ_SM_MISC_CFG0),
+				     NPU2_MISC_DA_LEN_8B);
+		/* Set OCAPI mode for bricks 2-5 */
+		reg |= NPU2_CQ_SM_MISC_CFG0_CONFIG_OCAPI_MODE;
+		npu2_scom_write(gcid, scom_base,
+				NPU2_REG_OFFSET(stack, block,
+						NPU2_CQ_SM_MISC_CFG0),
+				NPU2_MISC_DA_LEN_8B, reg);
+	}
+}
+
+static void enable_xsl_xts_interfaces(uint32_t gcid, uint32_t scom_base, int index)
+{
+	uint64_t reg;
+
+	prlog(PR_DEBUG, "OCAPI: %s: Enable XSL-XTS Interfaces\n", __func__);
+	/* Step 7 - Enable XSL-XTS interfaces */
+	/* XTS Config Register - Enable XSL-XTS interface */
+	reg = npu2_scom_read(gcid, scom_base, NPU2_XTS_CFG, NPU2_MISC_DA_LEN_8B);
+	reg |= NPU2_XTS_CFG_OPENCAPI;
+	npu2_scom_write(gcid, scom_base, NPU2_XTS_CFG, NPU2_MISC_DA_LEN_8B, reg);
+
+	/* XTS Config2 Register - Enable XSL1/2 */
+	reg = npu2_scom_read(gcid, scom_base, NPU2_XTS_CFG2, NPU2_MISC_DA_LEN_8B);
+	switch (index_to_stack(index)) {
+	case NPU2_STACK_STCK_1:
+		reg |= NPU2_XTS_CFG2_XSL1_ENA;
+		break;
+	case NPU2_STACK_STCK_2:
+		reg |= NPU2_XTS_CFG2_XSL2_ENA;
+		break;
+	}
+	npu2_scom_write(gcid, scom_base, NPU2_XTS_CFG2, NPU2_MISC_DA_LEN_8B, reg);
+}
+
+static void enable_sm_allocation(uint32_t gcid, uint32_t scom_base, int index)
+{
+	uint64_t reg, block;
+	int stack = index_to_stack(index);
+
+	prlog(PR_DEBUG, "OCAPI: %s: Enable State Machine Allocation\n", __func__);
+	/* Step 8 - Enable state-machine allocation */
+	/* Low-Water Marks Registers - Enable state machine allocation */
+	for (block = NPU2_BLOCK_SM_0; block <= NPU2_BLOCK_SM_3; block++) {
+		reg = npu2_scom_read(gcid, scom_base,
+				     NPU2_REG_OFFSET(stack, block,
+						     NPU2_LOW_WATER_MARKS),
+				     NPU2_MISC_DA_LEN_8B);
+		reg |= NPU2_LOW_WATER_MARKS_ENABLE_MACHINE_ALLOC;
+		npu2_scom_write(gcid, scom_base,
+				NPU2_REG_OFFSET(stack, block,
+						NPU2_LOW_WATER_MARKS),
+				NPU2_MISC_DA_LEN_8B, reg);
+	}
+}
+
+static void enable_pb_snooping(uint32_t gcid, uint32_t scom_base, int index)
+{
+	uint64_t reg, block;
+	int stack = index_to_stack(index);
+
+	prlog(PR_DEBUG, "OCAPI: %s: Enable PowerBus snooping\n", __func__);
+	/* Step 9 - Enable PowerBus snooping */
+	/* CQ_SM Misc Config Register #0 - Enable PowerBus snooping */
+	for (block = NPU2_BLOCK_SM_0; block <= NPU2_BLOCK_SM_3; block++) {
+		reg = npu2_scom_read(gcid, scom_base,
+				     NPU2_REG_OFFSET(stack, block,
+						     NPU2_CQ_SM_MISC_CFG0),
+				     NPU2_MISC_DA_LEN_8B);
+		reg |= NPU2_CQ_SM_MISC_CFG0_CONFIG_ENABLE_PBUS;
+		npu2_scom_write(gcid, scom_base,
+				NPU2_REG_OFFSET(stack, block,
+						NPU2_CQ_SM_MISC_CFG0),
+				NPU2_MISC_DA_LEN_8B, reg);
+	}
+}
+
+static void brick_config(uint32_t gcid, uint32_t scom_base, int index)
+{
+	/*
+	 * We assume at this point that the PowerBus Hotplug Mode Control
+	 * register is correctly set by Hostboot
+	 */
+	set_transport_mux_controls(gcid, scom_base, index,
+				   NPU2_DEV_TYPE_OPENCAPI);
+	enable_odl_phy_mux(gcid, index);
+	disable_alink_fp(gcid);
+	enable_xsl_clocks(gcid, scom_base, index);
+	set_npcq_config(gcid, scom_base, index);
+	enable_xsl_xts_interfaces(gcid, scom_base, index);
+	enable_sm_allocation(gcid, scom_base, index);
+	enable_pb_snooping(gcid, scom_base, index);
+}
+
+/* Procedure 13.1.3.5 - TL Configuration */
+static void tl_config(uint32_t gcid, uint32_t scom_base, uint64_t index)
+{
+	uint64_t reg;
+	uint64_t stack = index_to_stack(index);
+	uint64_t block = index_to_block(index);
+
+	prlog(PR_DEBUG, "OCAPI: %s: TL Configuration\n", __func__);
+	/* OTL Config 0 Register */
+	reg = 0;
+	/* OTL Enable */
+	reg |= NPU2_OTL_CONFIG0_EN;
+	/* Block PE Handle from ERAT Index */
+	reg |= NPU2_OTL_CONFIG0_BLOCK_PE_HANDLE;
+	/* OTL Brick ID */
+	reg = SETFIELD(NPU2_OTL_CONFIG0_BRICKID, reg, index - 2);
+	/* ERAT Hash 0 */
+	reg = SETFIELD(NPU2_OTL_CONFIG0_ERAT_HASH_0, reg, 0b011001);
+	/* ERAT Hash 1 */
+	reg = SETFIELD(NPU2_OTL_CONFIG0_ERAT_HASH_1, reg, 0b000111);
+	/* ERAT Hash 2 */
+	reg = SETFIELD(NPU2_OTL_CONFIG0_ERAT_HASH_2, reg, 0b101100);
+	/* ERAT Hash 3 */
+	reg = SETFIELD(NPU2_OTL_CONFIG0_ERAT_HASH_3, reg, 0b100110);
+	npu2_scom_write(gcid, scom_base, NPU2_OTL_CONFIG0(stack, block),
+			NPU2_MISC_DA_LEN_8B, reg);
+
+	/* OTL Config 1 Register */
+	reg = 0;
+	/*
+	 * We leave Template 1-3 bits at 0 to force template 0 as required
+	 * for unknown devices.
+	 *
+	 * Template 0 Transmit Rate is set to most conservative setting which
+	 * will always be supported. Other Template Transmit rates are left
+	 * unset and will be set later by OS.
+	 */
+	reg = SETFIELD(NPU2_OTL_CONFIG1_TX_TEMP0_RATE, reg, 0b1111);
+	/* Extra wait cycles TXI-TXO */
+	reg = SETFIELD(NPU2_OTL_CONFIG1_TX_DRDY_WAIT, reg, 0b001);
+	/* Minimum Frequency to Return TLX Credits to AFU */
+	reg = SETFIELD(NPU2_OTL_CONFIG1_TX_CRET_FREQ, reg, 0b001);
+	/* Frequency to add age to Transmit Requests */
+	reg = SETFIELD(NPU2_OTL_CONFIG1_TX_AGE_FREQ, reg, 0b11000);
+	/* Response High Priority Threshold */
+	reg = SETFIELD(NPU2_OTL_CONFIG1_TX_RS2_HPWAIT, reg, 0b011011);
+	/* 4-slot Request High Priority Threshold */
+	reg = SETFIELD(NPU2_OTL_CONFIG1_TX_RQ4_HPWAIT, reg, 0b011011);
+	/* 6-slot Request High Priority */
+	reg = SETFIELD(NPU2_OTL_CONFIG1_TX_RQ6_HPWAIT, reg, 0b011011);
+	/* Stop the OCAPI Link on Uncorrectable Error
+	 * TODO: Confirm final value - disabled for debug */
+
+	npu2_scom_write(gcid, scom_base, NPU2_OTL_CONFIG1(stack, block),
+			NPU2_MISC_DA_LEN_8B, reg);
+
+	/* TLX Credit Configuration Register */
+	reg = 0;
+	/* VC0/VC3/DCP0/DCP1 credits to send to AFU */
+	reg = SETFIELD(NPU2_OTL_TLX_CREDITS_VC0_CREDITS, reg, 0x40);
+	reg = SETFIELD(NPU2_OTL_TLX_CREDITS_VC3_CREDITS, reg, 0x40);
+	reg = SETFIELD(NPU2_OTL_TLX_CREDITS_DCP0_CREDITS, reg, 0x80);
+	reg = SETFIELD(NPU2_OTL_TLX_CREDITS_DCP1_CREDITS, reg, 0x80);
+	npu2_scom_write(gcid, scom_base, NPU2_OTL_TLX_CREDITS(stack, block),
+			NPU2_MISC_DA_LEN_8B, reg);
+}
+
+/* Detect Nimbus DD2.0 and DD2.01 */
+static int get_nimbus_level(void)
+{
+	struct proc_chip *chip = next_chip(NULL);
+
+	if (chip && chip->type == PROC_CHIP_P9_NIMBUS)
+		return chip->ec_level & 0xff;
+	return -1;
+}
+
+/* Procedure 13.1.3.6 - Address Translation Configuration */
+static void address_translation_config(uint32_t gcid, uint32_t scom_base,
+				       uint64_t index)
+{
+	int chip_level;
+	uint64_t reg;
+	uint64_t stack = index_to_stack(index);
+
+	prlog(PR_DEBUG, "OCAPI: %s: Address Translation Configuration\n", __func__);
+	/* PSL_SCNTL_A0 Register */
+	/*
+	 * ERAT shared between multiple AFUs
+	 *
+	 * The workbook has this bit around the wrong way from the hardware.
+	 *
+	 * TODO: handle correctly with link ganging
+	 */
+	reg = npu2_scom_read(gcid, scom_base,
+			     NPU2_REG_OFFSET(stack, NPU2_BLOCK_XSL,
+					     NPU2_XSL_PSL_SCNTL_A0),
+			     NPU2_MISC_DA_LEN_8B);
+	reg |= NPU2_XSL_PSL_SCNTL_A0_MULTI_AFU_DIAL;
+	npu2_scom_write(gcid, scom_base,
+			NPU2_REG_OFFSET(stack, NPU2_BLOCK_XSL,
+					NPU2_XSL_PSL_SCNTL_A0),
+			NPU2_MISC_DA_LEN_8B, reg);
+
+	chip_level = get_nimbus_level();
+	if (chip_level == 0x20) {
+		/*
+		 * Errata HW408041 (section 15.1.10 of NPU workbook)
+		 * "RA mismatch when both tlbie and checkout response
+		 * are seen in same cycle"
+		 */
+		/* XSL_GP Register - Bloom Filter Disable */
+		reg = npu2_scom_read(gcid, scom_base,
+				NPU2_REG_OFFSET(stack, NPU2_BLOCK_XSL, NPU2_XSL_GP),
+				NPU2_MISC_DA_LEN_8B);
+		/* To update XSL_GP, we must first write a magic value to it */
+		npu2_scom_write(gcid, scom_base,
+				NPU2_REG_OFFSET(stack, NPU2_BLOCK_XSL, NPU2_XSL_GP),
+				NPU2_MISC_DA_LEN_8B, 0x0523790323000000);
+		reg &= ~NPU2_XSL_GP_BLOOM_FILTER_ENABLE;
+		npu2_scom_write(gcid, scom_base,
+				NPU2_REG_OFFSET(stack, NPU2_BLOCK_XSL, NPU2_XSL_GP),
+				NPU2_MISC_DA_LEN_8B, reg);
+	}
+
+	if (chip_level == 0x20 || chip_level == 0x21) {
+		/*
+		 * DD2.0/2.1 EOA Bug. Fixed in DD2.2
+		 */
+		reg = 0x32F8000000000001;
+		npu2_scom_write(gcid, scom_base,
+				NPU2_REG_OFFSET(stack, NPU2_BLOCK_XSL,
+						NPU2_XSL_DEF),
+				NPU2_MISC_DA_LEN_8B, reg);
+	}
+}
+
+/* TODO: Merge this with NVLink implementation - we don't use the npu2_bar
+ * wrapper for the PHY BARs yet */
+static void write_bar(uint32_t gcid, uint32_t scom_base, uint64_t reg,
+		      uint64_t addr, uint64_t size)
+{
+	uint64_t val;
+	int block;
+	switch (NPU2_REG(reg)) {
+	case NPU2_PHY_BAR:
+		val = SETFIELD(NPU2_PHY_BAR_ADDR, 0ul, addr >> 21);
+		val = SETFIELD(NPU2_PHY_BAR_ENABLE, val, 1);
+		break;
+	case NPU2_NTL0_BAR:
+	case NPU2_NTL1_BAR:
+		val = SETFIELD(NPU2_NTL_BAR_ADDR, 0ul, addr >> 16);
+		val = SETFIELD(NPU2_NTL_BAR_SIZE, val, ilog2(size >> 16));
+		val = SETFIELD(NPU2_NTL_BAR_ENABLE, val, 1);
+		break;
+	case NPU2_GENID_BAR:
+		val = SETFIELD(NPU2_GENID_BAR_ADDR, 0ul, addr >> 16);
+		val = SETFIELD(NPU2_GENID_BAR_ENABLE, val, 1);
+		break;
+	default:
+		val = 0ul;
+	}
+
+	for (block = NPU2_BLOCK_SM_0; block <= NPU2_BLOCK_SM_3; block++) {
+		npu2_scom_write(gcid, scom_base, NPU2_REG_OFFSET(0, block, reg),
+				NPU2_MISC_DA_LEN_8B, val);
+		prlog(PR_DEBUG, "OCAPI: Setting BAR %llx to %llx\n",
+		      NPU2_REG_OFFSET(0, block, reg), val);
+	}
+}
+
+static void setup_global_mmio_bar(uint32_t gcid, uint32_t scom_base,
+				  uint64_t reg[])
+{
+	uint64_t addr, size;
+
+	prlog(PR_DEBUG, "OCAPI: patching up PHY0 bar, %s\n", __func__);
+	phys_map_get(gcid, NPU_PHY, 0, &addr, &size);
+	write_bar(gcid, scom_base,
+		  NPU2_REG_OFFSET(NPU2_STACK_STCK_2, 0, NPU2_PHY_BAR),
+		addr, size);
+	prlog(PR_DEBUG, "OCAPI: patching up PHY1 bar, %s\n", __func__);
+	phys_map_get(gcid, NPU_PHY, 1, &addr, &size);
+	write_bar(gcid, scom_base,
+		  NPU2_REG_OFFSET(NPU2_STACK_STCK_1, 0, NPU2_PHY_BAR),
+		addr, size);
+
+	prlog(PR_DEBUG, "OCAPI: setup global mmio, %s\n", __func__);
+	phys_map_get(gcid, NPU_REGS, 0, &addr, &size);
+	write_bar(gcid, scom_base,
+		  NPU2_REG_OFFSET(NPU2_STACK_STCK_0, 0, NPU2_PHY_BAR),
+		addr, size);
+	reg[0] = addr;
+	reg[1] = size;
+}
+
+static void mask_nvlink_fir(struct npu2 *p)
+{
+	uint64_t reg;
+
+	/*
+	 * From section 13.1.3.10 of the NPU workbook: "the NV-Link
+	 * Datalink Layer Stall and NoStall signals are used for a
+	 * different purpose when the link is configured for
+	 * OpenCAPI. Therefore, the corresponding bits in NPU FIR
+	 * Register 1 must be masked and configured to NOT cause the
+	 * NPU to go into Freeze or Fence mode or send an Interrupt."
+	 *
+	 * FIXME: will need to revisit when mixing nvlink with
+	 * opencapi. Assumes an opencapi-only setup on both PHYs for
+	 * now.
+	 */
+
+	/* Mask FIRs */
+	xscom_read(p->chip_id, p->xscom_base + NPU2_MISC_FIR_MASK1, &reg);
+	reg = SETFIELD(PPC_BITMASK(0, 11), reg, 0xFFF);
+	xscom_write(p->chip_id, p->xscom_base + NPU2_MISC_FIR_MASK1, reg);
+
+	/* freeze disable */
+	reg = npu2_scom_read(p->chip_id, p->xscom_base,
+			NPU2_MISC_FREEZE_ENABLE1, NPU2_MISC_DA_LEN_8B);
+	reg = SETFIELD(PPC_BITMASK(0, 11), reg, 0);
+	npu2_scom_write(p->chip_id, p->xscom_base,
+			NPU2_MISC_FREEZE_ENABLE1, NPU2_MISC_DA_LEN_8B, reg);
+
+	/* fence disable */
+	reg = npu2_scom_read(p->chip_id, p->xscom_base,
+			NPU2_MISC_FENCE_ENABLE1, NPU2_MISC_DA_LEN_8B);
+	reg = SETFIELD(PPC_BITMASK(0, 11), reg, 0);
+	npu2_scom_write(p->chip_id, p->xscom_base,
+			NPU2_MISC_FENCE_ENABLE1, NPU2_MISC_DA_LEN_8B, reg);
+
+	/* irq disable */
+	reg = npu2_scom_read(p->chip_id, p->xscom_base,
+			NPU2_MISC_IRQ_ENABLE1, NPU2_MISC_DA_LEN_8B);
+	reg = SETFIELD(PPC_BITMASK(0, 11), reg, 0);
+	npu2_scom_write(p->chip_id, p->xscom_base,
+			NPU2_MISC_IRQ_ENABLE1, NPU2_MISC_DA_LEN_8B, reg);
+}
+
+static int setup_irq(struct npu2 *p)
+{
+	uint64_t reg, mmio_addr;
+	uint32_t base;
+
+	base = xive_alloc_ipi_irqs(p->chip_id, NPU_IRQ_LEVELS, 64);
+	if (base == XIVE_IRQ_ERROR) {
+		/**
+		 * @fwts-label OCAPIIRQAllocationFailed
+		 * @fwts-advice OpenCAPI IRQ setup failed. This is probably
+		 * a firmware bug. OpenCAPI functionality will be broken.
+		 */
+		prlog(PR_ERR, "OCAPI: Couldn't allocate interrupts for NPU\n");
+		return -1;
+	}
+	p->irq_base = base;
+
+	xive_register_ipi_source(base, NPU_IRQ_LEVELS, NULL, NULL);
+	mmio_addr = (uint64_t ) xive_get_trigger_port(base);
+	prlog(PR_DEBUG, "OCAPI: NPU base irq %d @%llx\n", base, mmio_addr);
+	reg = (mmio_addr & NPU2_MISC_IRQ_BASE_MASK) << 13;
+	npu2_scom_write(p->chip_id, p->xscom_base, NPU2_MISC_IRQ_BASE,
+			NPU2_MISC_DA_LEN_8B, reg);
+	/*
+	 * setup page size = 64k
+	 *
+	 * OS type is set to AIX: opal also runs with 2 pages per interrupt,
+	 * so to cover the max offset for 35 levels of interrupt, we need
+	 * bits 41 to 46, which is what the AIX setting does. There's no
+	 * other meaning for that AIX setting.
+	 */
+	reg = npu2_scom_read(p->chip_id, p->xscom_base, NPU2_MISC_CFG,
+			NPU2_MISC_DA_LEN_8B);
+	reg |= NPU2_MISC_CFG_IPI_PS;
+	reg &= ~NPU2_MISC_CFG_IPI_OS;
+	npu2_scom_write(p->chip_id, p->xscom_base, NPU2_MISC_CFG,
+			NPU2_MISC_DA_LEN_8B, reg);
+
+	/* enable translation interrupts for all bricks */
+	reg = npu2_scom_read(p->chip_id, p->xscom_base, NPU2_MISC_IRQ_ENABLE2,
+			     NPU2_MISC_DA_LEN_8B);
+	reg |= PPC_BIT(0) | PPC_BIT(1) | PPC_BIT(2) | PPC_BIT(3);
+	npu2_scom_write(p->chip_id, p->xscom_base, NPU2_MISC_IRQ_ENABLE2,
+			NPU2_MISC_DA_LEN_8B, reg);
+
+	mask_nvlink_fir(p);
+	return 0;
+}
+
+static void npu2_opencapi_probe(struct dt_node *dn)
+{
+	struct dt_node *link;
+	char *path;
+	uint32_t gcid, index, links, scom_base;
+	uint64_t reg[2];
+	uint64_t dev_index;
+	struct npu2 *n;
+	int rc;
+
+	path = dt_get_path(dn);
+	gcid = dt_get_chip_id(dn);
+	index = dt_prop_get_u32(dn, "ibm,npu-index");
+	links = dt_prop_get_u32(dn, "ibm,npu-links");
+
+	/* Don't try to init when we have an NVLink link */
+	dt_for_each_compatible(dn, link, "ibm,npu-link") {
+		prlog(PR_DEBUG, "OCAPI: NPU%d: NVLink link found, skipping\n",
+		      index);
+		return;
+	}
+
+	prlog(PR_INFO, "OCAPI: Chip %d Found OpenCAPI NPU%d (%d links) at %s\n",
+	      gcid, index, links, path);
+	free(path);
+
+	/* TODO: Test OpenCAPI with fast reboot and make it work */
+	disable_fast_reboot("OpenCAPI device enabled");
+
+	scom_base = dt_get_address(dn, 0, NULL);
+	prlog(PR_INFO, "OCAPI:	 SCOM Base:  %08x\n", scom_base);
+
+	setup_global_mmio_bar(gcid, scom_base, reg);
+
+	n = zalloc(sizeof(struct npu2) + links * sizeof(struct npu2_dev));
+	n->devices = (struct npu2_dev *)(n + 1);
+	n->chip_id = gcid;
+	n->xscom_base = scom_base;
+	n->regs = (void *)reg[0];
+	n->dt_node = dn;
+
+	dt_for_each_compatible(dn, link, "ibm,npu-link-opencapi") {
+		dev_index = dt_prop_get_u32(link, "ibm,npu-link-index");
+		prlog(PR_INFO, "OCAPI: Configuring link index %lld\n",
+		      dev_index);
+
+		/* Procedure 13.1.3.1 - Select OCAPI vs NVLink */
+		brick_config(gcid, scom_base, dev_index);
+
+		/* Procedure 13.1.3.5 - Transaction Layer Configuration */
+		tl_config(gcid, scom_base, dev_index);
+
+		/* Procedure 13.1.3.6 - Address Translation Configuration */
+		address_translation_config(gcid, scom_base, dev_index);
+	}
+
+	/* Procedure 13.1.3.10 - Interrupt Configuration */
+	rc = setup_irq(n);
+	if (rc)
+		goto failed;
+
+	return;
+failed:
+	free(n);
+}
+
+void probe_npu2_opencapi(void)
+{
+	struct dt_node *np_npu;
+
+	dt_for_each_compatible(dt_root, np_npu, "ibm,power9-npu")
+		npu2_opencapi_probe(np_npu);
+}
diff --git a/hw/npu2.c b/hw/npu2.c
index 5ee55b4..daaae20 100644
--- a/hw/npu2.c
+++ b/hw/npu2.c
@@ -1301,6 +1301,15 @@ static void npu2_probe_phb(struct dt_node *dn)
 	uint64_t reg[2], mm_win[2];
 	char *path;
 
+	/* Abort if any OpenCAPI links detected */
+	if (dt_find_compatible_node(dn, NULL, "ibm,npu-link-opencapi")) {
+		/* Die if there's also an NVLink link */
+		assert(!dt_find_compatible_node(dn, NULL, "ibm,npu-link"));
+		prlog(PR_INFO, "NPU2: OpenCAPI link configuration detected, "
+		      "not initialising NVLink\n");
+		return;
+	}
+
 	/* Retrieve chip id */
 	path = dt_get_path(dn);
 	gcid = dt_get_chip_id(dn);